-Balaclava-clad intruder 'broke in and attached device to Madeleine Pulver' -No explosives had been found in the device -Shaken parents waited outside house before reunion with daughter-Family is one of Sydney's wealthiest with mansion in exclusive street -Bomb officers investigating other 'items' in house -Father one of Sydney's most wealthy men, William Pulver, CEO of an internet share dealing company, called Nielsen Net Ratings -Family has recently moved back from New York

By Richard Shears

An Australian schoolgirl spent ten terrifying hours with a ‘collar bomb’ strapped to her neck while police tried to defuse it yesterday.

Madeleine Pulver’s ordeal began when a hooded raider broke into her wealthy family’s home and attached the explosive device.

The attacker was reported to have left a ransom note for her father – the millionaire boss of an international software company – threatening to set off the bomb if money wasn’t paid.

However, police last night declined to say whether the device had been part of an extortion attempt.

They said they and the family had no ideas as to a motive and also revealed Miss Pulver had had ‘previous contact’ with the raider.

It was reported the man also warned the 18-year-old against calling police by saying he had attached a microphone to her so he could hear what she said.

He was also said to have told her he could detonate the device remotely.

Despite the warning, Miss Pulver called police who then embarked on a delicate ten-hour operation to remove the bomb.

The device was so elaborate that experts had no idea whether it would explode as they attempted to detach it.

Miss Pulver was said to have been ‘absolutely petrified’ during the ordeal.

Police bomb disposal experts, who had sought advice from British military authorities as they delicately worked to free Madeleine Pulver from the explosive package that had been attached to her, finally freed her from her terrifying ordeal - into the arms of her relieved mother and father.

The 18-year-old girl had been startled by the balaclava-clad intruder who left the device attached to her - as well as leaving, it is believed, a ransom note for her wealthy parents.

Her father, William, is the CEO of an internet share dealing company, called Nielsen Net Ratings and is said to be one of the richest men in Australia.

Her mother, Belinda, 51, has a succesful landscaping company. The family has recently moved back from New York.

Today's drama was played out in the exclusive Sydney suburb of Mosman - home of multi-millionaires, sports figures, stockbrokers and bankers.

After finally being reunited with her parents Madeleine Pulver was rushed to hospital where doctors could examine the teenager

The intruder sneaked into the family's luxurious home and is understood to have strapped a 'device and a note' to the terrified schoolgirl's throat

Police assistant commissioner Mark Murdoch refused to comment on claims that a ransom note was left with the device. ‘The family are at a loss to explain this,’ he said. ‘You would hardly think that someone would go to this much trouble if there wasn’t a motive behind it.

‘We want to get our hands on who’s done this.’ Even after the device was removed, Mr Murdoch said bomb squad officers still did not know how dangerous it was.

But he indicated that it was not a fake bomb. ‘It was examined right away for explosives and the delicate action we have taken in regard to it shows how serious the situation was.’

Neither he nor the bomb squad officers had seen anything like it and he admitted it would be ‘some time’ before it could be dismantled, not only for safety reasons, but to look for clues as to who had put it together.

During the efforts to free Miss Pulver, Mr Murdoch said no one claiming to have left the device contacted police.

He said the teenager was ‘doing well’ after being freed and was reunited with her parents, who had been kept out of the house by police during the ordeal for their own safety. Miss Pulver was taken to a hospital for an examination.

‘She’s good – she’s been kept in a very uncomfortable position,’ Mr Murdoch said. ‘She has been and will be uncomfortable for a little while to come.’

Mr Murdoch admitted last night in the minutes after the girl was released from the device that bomb squad officers still did not know how dangerous it was.

But he indicated that it was not a fake device. 'It was examined right away for explosives and the delicate action we have taken in regard to it shows how serious the situation was,' he said.

Tight knit: Madeleine Pulver, seen with her father Bill was examined by police and bomb experts while her parents had to wait for her rescue outside

Mr Murdoch said neither he nor the trained bomb squad officers had seen a device like it before

'It is a very elaborate device and remains so. Our bomb technicians are one of the best in the world and it has taken them more than 10 hours to remove it.'

The tension that had been on Mr Murdoch's face throughout the afternoon and evening in Australia fell away last night when he announced at midnight that 'minutes ago we have secured the release of the young lady and she is safe and sound. She has been reunited with her parents.'

The privately-schooled girl, who had moved back to Australia with her family from New York, was due to be examined by doctors overnight.

'She's in good hands, with mum and dad,' Mr Murdoch told a press conference today.'They're the most important people for her to be with right now.

'The family has endured something no one needs to endure and, as a parent, something I could never contemplate.'

Tense: Police and bomb officers stood outside the mansion in, Mosman, Sydney where the 18-year-old girl had a bomb strapped to her collar

Nail-biting: Police officers, wearing protective equipment, had to spend hours trying to work out what the device was and how to free the terrified teenager

Holding their breath: While experts tried to free Madeleine, her parents waited outside and comforted each other

Police were scouring other 'items' inside the house while they moved Miss Pulver to the front part of the building.

There were some suggestions that the drama mirrored a scene from the horror movie Saw and an episode of the CSI crime show.

Police have not given any official details about the intruder, but officers confirmed that a stranger wearing a balaclava had entered the house and left a 'package' with her.

Assessing how dangerous it is, Mr Murdoch said the operation 'demands a high level of skill and must be meticulous'.

The high drama, which has stunned residents living in the leafy suburb where the value of many of the homes run into millions of dollars, began when the girl, who was home alone when the man entered, phoned police at about 2.30pm.

Delicate: Police cordoned off the street as the terrified girl's parents looked on. It is understood the wealthy family was being held to ransom

Emergency: Bomb officers spent ten hours trying to work out how they could diffuse the explosive device which had a note attached to it

Such was the concern about the package that police have cordoned off the house and closed a number of nearby streets. Some houses nearby have also been evacuated.

Assistant Commissioner Murdoch said at the time: 'We are still treating the suspicious package as live.

'I can't confirm whether it is strapped to the woman involved but she is still in the vicinity of the device.'

Asked if she could move away from the device, Mr Murdoch said: 'No, she can't get away from it.'

He said police had to 'hasten slowly' in a delicate situation like this.

Assistant Commissioner Murdoch emerged from the large house at 8.40pm Australian time to confirm that the young woman was still inside, in a front room, and the volatility of the device had still not been determined.

‘The young lady remains in the house with the device and specialist police are trying to verify what we are dealing with,' he said.

‘Until we know what we are dealing with we will treat it with the utmost seriousness.‘There are good operational reasons for us to continue playing our cards close to our chest.’

Mr Murdoch said police had found ‘some items’ in the house that were being examined and he confirmed that among the detectives involved in the drama were men from the Robbery and Serious Crime Squad who deal with extortion.

‘We are working hard to find out exactly what it is and equally importantly what it isn’t,’ said Mr Murdoch.

The young woman, he said, was ‘going pretty well’ and had specialist police with her.

Darkness: Temporary lights were used to conduct the operation while inside the multi-million pound property bomb officers tried to calm the girl

Battle: Police continued their efforts to free the teenager from the 'ransom' bomb as night fell on Burrawong Avenue in Mosman, Sydney

‘We need to be very careful about what we say and do…we have to have it resolved as quickly as possible for the sake of the young lady and her family.’

Mr Murdoch said later - some 10 hours after the intruder is believed to have entered the house - that the device was proving to be 'a tough nut to crack'.

Four police officers, including two bomb specialists, were with the girl but Mr Murdoch said he could not estimate how long the drama would continue for.

'We are continuing to work very very hard under difficult circumstances and we are working very hard to ensure the welfare of the family.

'This operation is serious, it is delicate and we will have to take as long as it takes to ensure this young lady's safety.'

At that time the teenager's parents have not been able to speak to their daughter, said Mr Murdoch, but he did not say why. There was speculation that a phone call might trigger an explosion if, in fact, explosives are involved in the drama.

The suburb of Mosman, where the famous Taronga Park Zoo is located, is on the northern shores of Sydney harbour. Huge homes line the leafy streets and the luxury yachts of the rich and powerful are moored in harbour inlets.

Madeleine is a student at the exclusive North Sydney private school Wenona, where her classmates are children of the super rich.

The family had a share in an historic 946ha grazing property, which sold two months ago for just under $3.7 million, and they own a ritzy Central Coast beachhouse.

At the time of the multi-million-dollar merger, Mr Pulver, chief executive of the new company, Appen Butler Hill, said the two companies could provide linguistic and voice-recognition services in more than 120 languages for clients including software companies, security organisations, as well as global government agencies.

Customers include Microsoft, IBM, Fujitsu, Toshiba and Telstra.

The neighbourhood's nearby shopping area, known as Mosman village, is the home of numerous boutiques selling high-priced designer labels.